Radio-frequency identification (RFID) tags use electromagnetic fields to wirelessly transfer data. RFID tags include an antenna and an RFID chip, which contains circuits for wirelessly receiving and sending data. The RFID chip is also encoded with data. A reader sends a radio signal to the RFID tag, which receives the signal and transmits its data to the reader. Some RFID tags receive their power from the radio signal sent by a RFID reader (i.e., passive). Other RFID tags are battery-powered (i.e., active). RFID tags can be used to track and identify objects, for example, vehicles.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.